Background: Alzheimer's disease (AD) involves impairment of Aβ clearance. Neprilysin (NEP) is the most efficient Aβ peptidase. Enhancement of the activity or expression of NEP may provide a prominent therapeutic strategy against AD.
Aims: Ten hydroxylated monocarbonyl curcumin derivatives were designed, synthesized and evaluated for their NEP upregulating potential using sensitive fluorescence-based Aβ digestion and inhibition assays.
Results: Compound 4 was the most active one, resulting in a 50% increase in Aβ cleavage activity. Cyclohexanone-bearing derivatives exhibited higher activity enhancement compared to their acetone counterparts. Inhibition experiments with the NEP-specific inhibitor thiorphan resulted in dramatic cleavage reduction.
Conclusion: The increased Aβ cleavage activity and the ease of synthesis of 4 renders it an extremely attractive lead compound.
Keywords: Alzheimer’s disease; Aβ amyloid peptide; amyloid cleavage; monocarbonyl curcumin derivatives; neprilysin.